Various miter devices have been proposed in the prior art. For example, Canadian patent 613,437 discloses a guide means for saws which is to be attached to a work bench. However, its constructions is relatively complex. Another patent, U.S. Pat. No. 3,842,700, teaches the use of an upper and lower plate to sandwich the board of plank to be cut. Other similar prior art are U.S. Pat. Nos. 3,379,228, 3,731,572; 4,007,657; and 4,320,678. A board which is not supported on both sides of a kerf has a tendency to splinter at right angles to the kerf, especially on the bottom surface of the board, and this is a major drawback of the prior art.